The present invention relates to a method of treating a parasitic infection, particularly endoparasitic filarial infections, in animals, using certain pentafluorothio)benzamide-acetonitrile derivatives, hereinafter aminoacetonitrile (AAD) derivatives or compounds of the present invention.
There is a continuing need to provide new agents for the control of parasitic infections that present a threat to human and animal health. In particular, new agents are needed to manage parasitic infections in animals due to the increasing prevalence of parasites, and in particular nematodes, that are resistant or becoming resistant to many of the agents currently approved for this indication. For example, the heartworm, Dirofilaria immitis, is showing both phenotypic and genotypic signs of resistance to macrocyclic lactones, a usual course of treatment.
The aminoacetonitrile derivatives of the present invention have been previously described generically and as examples in U.S. Pat. No. 7,608,604, U.S. Pat. No. 7,622,500, and U.S. Pat. No. 8,168,681. Specific aminoacetonitrile derivatives and uses thereof as antiparasiticides in animals and/or plants have been disclosed in international patent application publications WO2010/056999, WO2008/144275, and WO2005/044784.
There remains a need for further compounds as alternative or improved therapeutic agents, particularly for the treatment of endoparasites, especially for filarial nematodes. Preferred compounds should be potent endoparasiticidal agents while presenting little or no toxicity to the host animal, and should exist in a physical form that is stable, non-hygroscopic and easily formulated. They should have high bioavailability, be metabolically stable and possess favorable pharmacokinetic properties. Heartworm data based on both the L4 larvae and microfilaria of D. immitis is presented herein.